Having both Elements 3.0 and 5.0 intalled ?

I have been using Photoshop Elements 3.0 for some time. I installed Elements 5.0 on the same computer a few days ago. Is there a down side in terms of the speed or efficency of my system to having both versions installed ? The hard drive space 3.0 occupies doesn't seem so large, but are there other issues that I'm unaware of ? Is RAM some how involved, etc., or is there no real downside to keeping both versions installed ? I'm asking because there may be some things I prefer to do in 3.0. Thanks, Jack P.S. I know though both versions are currently installed, I cannot have them both open at the same time.

No help yet ???
I've had two versions of PS installed in the past with no ill effects, but the older version didn't stay around very long.
I can't image any down side to having both installed ... besides chewing up disc space.
I'm curious ... What could PSE 3 possibly have that PSE 5 can't do ???

The "undo" and "redo" are missing from the top bar in Edit in 5.0. Not a big deal as ctrl+Z , and ctrl+Y work easily. Otherwise not sure, just loved working with 3.0, and thought I might come upon other instances where I preferred the configuration/function of 3.0 - as a hedge in other words. I added 5.0 mainly for its' lens distortion correction tool. The more I use it ( it's been about a week now ) the more I see it as an improvement in a number of areas. I may uninstall 3.0, or wait awhile. It doesn't seem to occupy much hard drive space. Thanks, Jack

What
My Undo and Redo are there.
This might depend if your Image is in a RGB or Indexed (gif) mode.
They sort of dance around if they're available or not .. PSE seems to know if they're usable at any time.

Like you say .. I always use the keyboard shorts anyway.

Attached Files:

Yes, thanks, I do see them in the edit window, but as you say one has to be in RGB mode, or some such to have them active. They aren't sort of always there and useable in the top bar like they were in 3.0. I'm just using ctrl+z and ctrl+y so I don't have to think about it - P.S. something I'm good at ! Thanks again, Jack